RSA Insurance Group and confectionery company Cadbury both bucked another slide in the market yesterday, but overall the FTSE 100 index recorded its worst week for six years on growing economic worries.

The widely watched US non-farm payroll numbers showed that 84,000 jobs were lost in August, higher than most forecasts of a 75,000 drop. Both June and July's job losses were revised upwards.

On top of the US figures, a warning from Nokia, the world's largest mobile phone maker, that consumer caution would hit its trading added to the growing concerns about the state of the global economy. So with Wall Street more than 80 points lower by the time London closed - following Thursday's 344 point drop - the FTSE 100 ended 121.4 points lower at 5240.7. Since Monday, the index has fallen by nearly 400 points, or 7%, a weekly loss not seen since July 2002 when the index dropped 8.48%. Miners were the main losers, as commodity prices fell to reflect the prospect of falling demand as economic growth declines. Kazakhmys lost 86.5p to 975.5p, rival Eurasian Natural Resources Corporation was down 66.5p to 805.5p and Ferrexpo - likely to lose its place in the leading index next week - fell 14p to 184p. Platinum specialist Johnson Matthey was the biggest loser in the FTSE 100, down 134p to £14.41 after a downgrade from Merrill Lynch.

But insurer RSA closed 4.5p higher at 162.8p as takeover talk refused to die down. Germany's Allianz and Zurich Financial Services were both mentioned as possible predators, as was Italy's Generali. Traders were talking of a price tag of around 195p a share.

As for Cadbury, it added 14p to 636p on talk it was moving closer to selling its Australian drinks business. Analysts said the division, which could be worth up to £500m, had been looking increasingly out of place since the company spun off its US beverages operations as Dr Pepper earlier this year.

Back among the fallers, banks continued to suffer on further worries about more credit crunch write-offs. This week's news that the European Central Bank was restricting the use of its emergency liquidity scheme also hit sentiment. Goldman Sachs did not help by issuing a sell note on rival Merrill Lynch, while Dresdner Kleinwort predicted that despite the recent spate of rights issues, banks would have to ask investors for more cash next year to support their balance sheets.

So Barclays fell 12p to 317.25p as Collins Stewart issued a sell note ahead of a presentation on 15 September by the bank's president, Bob Diamond. The broker said: "We remain concerned about some big numbers on the balance sheet, for example the £5bn of leveraged finance and £11bn of commercial mortgages left." Royal Bank of Scotland slipped 8p to 219.75p, while HBOS lost 7p to 275.5p.

Supermarket group J Sainsbury was also among the losers, down 11.5p to 336p. Deutsche Bank moved from hold to sell and cut its price target from 335p to 310p, reflecting tougher times for the sector generally and the growing trend of customers to trade down from Sainsbury to discounters such as Aldi and Lidl.

Former government minister Patricia Hewitt - who joined the board of BT in March with a £60,000 a year salary - has just paid £5,000 to buy 2,830 shares. But the news had little effect on BT, which closed 3.4p lower at 169.1p.

Among the mid-caps, publishing group Informa fell back folllowing its after-hours rejection on Thursday of a 450p offer from a consortium including Carlyle Group and Providence Equity Partners. Despite analysts suggesting the consortium could return with a slightly higher offer of perhaps 475p, Informa closed 28.75p lower at 385.75p.

The Nokia warning sent shares in CSR, the bluetooth specialist which supplies mobile phone companies, tumbling 21.75p to 305.25p. Comet owner Kesa Electricals slipped 3.5p to 147.5p as JP Morgan cut its profit forecasts, partly to reflect a deterioration in the company's French business, and reduced its price target from 200p to 185p.

But Russia-focused oil and gas producer Imperial Energy jumped 25p to £11.55 on hopes that a takeover from India's state-owned ONGC could be concluded within the next four or five weeks.

On Aim, Churchill Mining climbed 7.5p to 66.5p on news that its East Kutai Coal project in Indonesia had reached 1.4bn tonnes of thermal coal, well ahead of its 500m target for 2008.

Blue Oar analyst Alison Stent said: "This is incredible news for Churchill. The 1.4bn tonne resource has been defined from drilling over only 20% of the total target area suggesting substantial further upside."

Medical equipment group Lombard Medical Technologies slumped 71% to 1.875p despite the company saying the fall was not a reflection of any change in its circumstances. It repeated that it was in discussions with a number of potential investors and expected new funds to be agreed in the coming months.

Racing Carr's

In contrast to most unscheduled updates - which tend to be profit warnings - Carr's Milling Industries yesterday issued its fourth upgrade in four months. Carr's, which supplies feed and fertilisers to farmers, is benefiting from rising food prices and now expects to make £12.5m for this year, up from £5.5m last year. Some £4m came from one-offs such as foreign exchange gains, but house broker Investec said underlying trading was strong and issued a buy note with a 760p target. Carr's has raised £2.7m for working capital with a 660p-a-share placing. It closed 15p higher at 677.5p.